Martin Freeman and Amanda Abbington also discuss how the on-screen couple is handling their new arrival.

This New Year’s Day, “Sherlock” starring Benedict Cumberbatch and Martin Freeman returns to television after three years since its last episode. Ahead of its debut, BBC released a behind the scenes video, which shows the duo, as well as Amanda Abbington and Una Stubbs, discussing this season’s adorable newcomer.

Season 4 of the acclaimed detective drama begins with Sherlock (Cumberbatch) back on British soil and Doctor Watson (Freeman) and his wife Mary (Abbington) preparing for their challenge of becoming parents.

The video begins with Sherlock’s reaction to the baby and how he feels very protective of the family.

“He’s not a natural parent or figure of authority when it comes to a new born,” says Cumberbatch. “But the seeming indifference, which is at times comic, is actually all underpinned with deep love.”

The video also shines light on Freeman and Abbington’s characters and how the on-screen couple is handling their new arrival.

“They’re very excited about it. They’re in a good place and a loving couple,” says Martin, with Abbington adding, “I think the impending baby is something they are both looking forward to a lot actually – including Sherlock, despite what he says.”

The upcoming three-episode season returns January 1 on PBS. Check out the video below.